This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-040621, filed Feb. 16, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an information recording medium such as an optical disk or the like. The present invention also relates to an information recording apparatus for recording objective information on the information recording medium of the present invention. Furthermore, the present invention relates to an information reproduction apparatus for reproducing objective information recorded on the information recording medium.
2. Description of the Related Art
In recent years, large-capacity information recording media such as DVD and the like have been extensively studied and developed. On a DVD-RAM that belongs to a DVD group, a single spiral track is formed. On the single spiral track, land and groove tracks alternately appear every rotation. Data is recorded on these tracks of the DVD-RAM in units called sectors. On a DVD-RAM, a pre-pit header (CAPA) is formed for each sector. The pre-pit header records address information by pre-pits. Japanese Patent Application No. 2000-303855 discloses a technique that pertains to the pre-pit header.
On the other hand, on a DVD-RW that belongs to the DVD group, no pre-pit headers are formed, and notched pits (land pre-pits) are formed on each land track (land portion) sandwiched between neighboring groove tracks. The land pre-pits indicate address information. In this case, an address is determined based on information from land pre-pits obtained by reproducing data for 16 sectors (=1 ECC block) as a whole. Jpn. Pat. Appln. KOKAI Publication No. 10-27349 discloses a technique that pertains to notched pits.
As described above, since the pre-pit header is formed on the DVD-RAM for each sector, the address can be determined for each sector upon reproducing the DVD-RAM. Also, concentric areas called zones are defined on the DVD-RAM, and 1,000 or more tracks are formed per zone. Pre-pit header fields are aligned in the radial direction within at least one zone. Therefore, even when tracking of a light beam has deviated from a target track during write, the next reproduction timing of a pre-pit header can be predicted. That is, by reading an address from the pre-pit header, any tracking error can be detected. In this manner, erroneous erasure (erroneous recording) due to such tracking errors during write can be restricted to one sector in the worst case. If an erroneously erased (recorded) region falls within one sector, it can be corrected by an ECC (Error Correction Code).
On the other hand, the DVD-RW has no pre-pits for each sector. When tracking of a light beam has deviated from a target track during write, a tracking error cannot be detected immediately. If a tracking error is to be detected based on an address determined by information from land pre-pits obtained by reproducing data for 16 sectors, erroneous erasure due to such tracking errors during write runs to a maximum of 16 sectors.
On the DVD-RAM, data destruction due to erroneous erasure caused by tracking errors during write is not so serious. However, since pre-pit headers are formed for respective sectors, the recording region of user data decreases. That is, the format efficiency lowers.
On the other hand, the DVD-RW does not suffer any format efficiency drop due to the header layout, since user data is continuously recorded on tracks. However, data destruction caused by tracking errors during write is likely to be serious.
That is, it is difficult for the conventional DVD-RAM and DVD-RW to attain both a reduction of the data destruction region due to erroneous erasure caused by tracking errors during write, and suppression of format efficiency drop.
It is an object of the present invention to provide an information recording medium that can solve the aforementioned problems.
(1) An information recording medium according to an embodiment of the present invention comprises a recording track, a plurality of address areas which are formed on the recording track and record address information, and mark areas, the number of which is larger than the number of address areas, and which are formed at predetermined intervals and include mark information.
(2) An information recording apparatus according to the embodiment of the present invention records objective information on an information recording medium,
the information recording medium comprises a recording track, a plurality of address areas which are formed on the recording track and record address information, and mark areas, the number of which is larger than the number of address areas, and which are formed at predetermined intervals and include mark information, and
the information recording apparatus according to the embodiment of the present invention comprises mark detection section configured to detecting the mark information from the mark areas, tracking control section configured to monitoring a tracking error based on the mark information detected by the mark detection section, and controlling a light beam to track the recording track, and recording section configured to reading the address information from the address areas, and recording predetermined information at a target position of the recording track on the basis of the read address information.
(3) An information reproduction apparatus according to the embodiment of the present invention reproduces objective information from an information recording medium,
the information recording medium comprises a recording track, a plurality of address areas which are formed on the recording track and record address information, and mark areas, the number of which is larger than the number of address areas, and which are formed at predetermined intervals and include mark information, and
the information reproduction apparatus according to the embodiment of the present invention comprises mark detection section configured to detecting the mark information from the mark areas, tracking control section configured to monitoring a tracking error based on the mark information detected by the mark detection section, and controlling a light beam to track the recording track, and reproduction section configured to reading the address information from the address areas, and reproducing predetermined information from a target position of the recording track on the basis of the read address information.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.